1. Field of the Invention
The present invention relates to a seeker head for a missile and more particularly to a stabilized seeker head using a fiber optic image relay having a wide field of regard.
2. Description of the Related Art
Missiles, projectiles, aircraft and the like that use imaging seekers normally mount a camera in a gimbal system in a forward portion of an air frame or missile casing, in order to obtain a wide field of regard for the camera optics. A common seeker head used in the prior art, comprising a camera mounted on a gimbal system, is shown in FIG. 1.
As shown in FIG. 1, a conventional seeker head 10 includes a cylindrical casing 11, having a centerline axis and a predetermined diameter, with a domed portion 12 at a forward end. Behind the domed portion and enclosed by the casing is a camera assembly 13, mounted on a gimbal assembly 14, including pitch and yaw torque motors, 15 and 16 respectively. The camera assembly 13 also comprises detector elements, associated camera electronics, and a protective case, mounted on the gimbal with the camera assembly, but not separately shown in FIG. 1. For some cameras, such as infrared imaging cameras, refrigeration devices may also be required.
Several drawbacks are associated with the conventional seeker head. The size of the camera assembly 13 limits seeker head performance. The physical dimensions of the camera assembly 13, relative to the casing 11, results in a field of regard restricted by the dimensions of the casing. The restricted field of regard, one half of which is shown as .theta..sub.1 for the camera assembly enables the conventional seeker head to see only up to 10.degree. on either side of the centerline axis as shown in FIG. 1.
Further, in order to stabilize the conventional seeker head of FIG. 1, it is necessary to balance the system in both the pitch and yaw reference planes. This generally requires use of inert counterweights 17 on the camera. The increased weight associated with the counterweights requires corresponding increases in power and size of the torque motors, 15 and 16, in order to maintain the desired frequency response of the seeker head.
Further, the larger torque motors, 15 and 16, place a larger drain on an available missile power supply (not shown).
The present invention improves on known seeker heads by providing a missile seeker head having a wide field of regard and rapid optical response for improved target searching and target tracking. The invention also provides a missile seeker head having reduced weight, thereby requiring smaller torque motors, thus reducing the power load on a missile electrical system.
Additional advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.